Au@Co 2 P core/shell nanoparticles as a nano-electrocatalyst for enhancing the oxygen evolution reaction.

Core/shell nanoparticles (NPs) of Au@Co 2 P, each comprising a Au core with a Co 2 P shell, were prepared, and shown to efficiently catalyze the oxygen evolution reaction (OER). In particular, Au@Co 2 P has a small overpotential of 321 mV at 10 mA cm -2 in 1 M KOH aqueous solution at room temperature, which is about 95 mV less than pure Co 2 P. More importantly, the Tafel slope of Au@Co 2 P, at 57 mV dec -1 , is 44 mV dec -1 lower than that of Co 2 P. Hence, Au@Co 2 P outperforms Co 2 P drastically in practical production when a high current density is required.